What is a Trojan Virus?
A Trojan is a category of virus or worm that can cause acute harm to your computer. It's a program that at primary glimpse may seem safe but in reality contains something quite damaging.
In fact it can ruin your computer by causing extensive damage and distribution. Trojans get into your computer by downloading apparently undamaging programs such as games, pictures, music or movie files, but once these programs are implemented, they begin to harm.
Trojans may initially do things to irritate you, but they can do worse injury if they want to. Trojans can remove damage your files, send your credit card numbers and passwords to an outsider or let others use your computer for unlawful functions.
There are two general types of Trojan horses. The first one is otherwise helpful software that has been corrupted by a cracker placing nasty code that executes while the program is used. Examples will include a range of implementations of weather-alerting programs, computer clock-setting software, and peer-to-peer file sharing utilities. The other type is a stand alone program that impersonates as something else, like a game or image file, in order to deceive the user into some misdirected participation that is needed to carry out the program's goals.
How Does The Infection Start?
Trojans are executable programs, which mean that when you open the file, it will execute some action(s). In Windows, executable programs have file extensions like "exe", "vbs", "com", "bat", etc. Some actual Trojan filenames include: "dmsetup.exe" and "LOVE-LETTER-FOR-YOU.TXT.vbs". Trojans can multiply in a semblance of literally anything people find attractive, such as a free game, movie, song, etc. Victims typically download the Trojan from a WWW or FTP archive, received from any peer-to-peer file exchange using IRC/instant messaging/Kazaa etc., or just carelessly open some email attachment. Trojans habitually do their harm noiselessly.
How Can I Avoid Being Infected?
You must be convinced of both the source and content of each file you download. You must never download blindly from people or sites, which you aren't totally sure about. Even if the file comes from a friend or acquaintance, you must still be sure what the file contains before opening it, because many trojans will mechanically try to multiply themselves to friends in an email address book or on an IRC channel.
There is rarely reason for a friend to send you a file that you didn't ask for. If you are uncertain, ask them first, and scan the attachment with a fully efficient anti-virus program. Be on the lookout for hidden extensions of executable files. Do not get complacent just because you have an anti-virus program. Many of them do not provide total security. Anti-virus programs should serve as a backup in case something sneaks into your computer.
How To Get Rid Of Trojans?
Although laborious, cleaning re-installation will always be the lone sure shot way to eliminate a Trojan virus. You need to back up your total hard disk, reformat it, re-install the operating system and all your applications from original CDs, and lastly, if you're convinced they are not infected, reinstate your user files from the backup.
Some of the anti virus software can handle most of the well-recognized trojans, but none of them are faultless. You must make sure that you use a full version of software with update facility and have your software updated. Compared to conventional viruses, today's trojans develop much faster and come in many apparently harmless forms. Anti-Trojan programs are the most efficient against Trojan horse assaults, because they focus specifically on Trojans instead of general viruses.
